Nampa weather in December

In December, Nampa sees average daytime highs of 40°F and overnight lows near 28°F, with 1.6 in of precipitation across 9.3 wet days and about 8.8 hours of daylight. It is the 12th-warmest and 1st-wettest month of the year here.

Highs ease over the month, from about 43°F in the first days to 39°F by the end. The sky is clear or mostly clear about 28% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 hours at the start of December to 8 h 48 min by month's end. Set against the rest of the year, December is Nampa's 10th-clearest and 6th-windiest month. For the whole year in context, see Nampa's year-round climate.

Daytime high
40°
12th warmest
Overnight low
28°
2nd coldest
Precipitation
1.6 in
9.3 wet days
Daylight
8 h 48 min
8:19 AM – 5:06 PM
Cloud cover
63%
10th clearest
Wind
6 mph
6th windiest
Solar energy
1.64 kWh/m²
Travel score
0.1
out of 10

Nampa is city in Canyon County, Idaho, United States.

Density
1,031/km²
people per km²
Founded
1886

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 43°F in the first days to 39°F by the end.

A typical December day in Nampa reaches about 40°F in the afternoon and slips back to 28°F overnight — a 13°F spread between the day's warmth and the night's chill. On most days the high lands between 31°F and 50°F. Set against its neighbours, December runs about 10°F cooler than November and on par with January.

20°30°40°50°60°151015202531
Avg high (°F)Avg low (°F)
14330
24329
34329
44229
54229
64229
74229
84129
94128
104128
114128
124128
134128
144028
154028
164028
174028
184028
194028
204028
214027
224027
233927
243927
253927
263927
273927
283927
293927
303927
313927

How December really feels in Nampa

Once humidity and wind are folded in, December averages 0 days that feel above 90°F and 31 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
31
wind chill below the day's low

The story in December is cold — wind chill drags the overnight "feels like" below the raw low.

Nampa weather by month

How December compares with the rest of the year at a glance. December is the 12th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan41° / 28°1.694.19.10.1
Feb47° / 31°1.07.32.210.21.6
Mar57° / 37°1.28.60.711.64.1
Apr64° / 42°1.16.40.113.26.2
May74° / 49°1.15.9014.57.5
Jun83° / 56°0.63.4015.27.0
Jul93° / 64°0.11014.94.0
Aug91° / 62°0.10.9013.84.6
Sep81° / 54°0.42012.37.9
Oct66° / 43°0.84.2010.87.0
Nov50° / 34°1.27.31.49.52.5
Dec40° / 28°1.69.348.80.1

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 28% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 15% of December, with mostly cloudy or overcast conditions the remaining 58%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14456
24456
34456
44456
54258
64258
74258
84258
94258
104258
114159
124159
134159
144159
154159
164258
174258
184357
194258
204258
214258
224258
234258
244258
254258
264258
274258
284258
294159
304159
314159

Chance of precipitation in December

Any precipitationSnow

Nampa gets around 1.6 in of rain and snow over 9.3 wet days in December, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 29% and peaks near 30% on the wettest days, and about 4 days bring snow.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
12911
22911
32911
42911
53011
63011
73011
83011
93011
103011
113011
123011
132911
142912
152912
162912
172913
182913
192913
202914
212914
222914
232914
242914
252914
262915
272915
282915
292915
302915
312915

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in December

Winds average 6 mph in December.

Across December, daily wind ranges from about 5 mph on the calmest days to 6 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 hours at the start of December to 8 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over December. Sunrise moves from 8:06 AM to 8:25 AM, and sunset from 5:06 PM to 5:13 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.08:065:06
29.08:075:06
39.08:085:06
48.98:095:05
58.98:105:05
68.98:115:05
78.98:125:05
88.98:135:05
98.98:145:05
108.88:155:05
118.88:155:05
128.88:165:05
138.88:175:05
148.88:185:05
158.88:185:05
168.88:195:06
178.88:205:06
188.88:205:06
198.88:215:07
208.88:225:07
218.88:225:07
228.88:235:08
238.88:235:08
248.88:235:09
258.88:245:09
268.88:245:10
278.88:245:11
288.88:255:11
298.88:255:12
308.88:255:13
318.88:255:13

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.64 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.64 kWh/m² to a high of 8.02 kWh/m² in July across the year — December's 1.64 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.8Dim
21.7Dim
31.7Dim
41.7Dim
51.7Dim
61.7Dim
71.7Dim
81.6Dim
91.6Dim
101.6Dim
111.6Dim
121.6Dim
131.6Dim
141.6Dim
151.6Dim
161.6Dim
171.6Dim
181.6Dim
191.6Dim
201.6Dim
211.6Dim
221.6Dim
231.6Dim
241.6Dim
251.6Dim
261.6Dim
271.7Dim
281.7Dim
291.7Dim
301.7Dim
311.7Dim
Planning a trip in December

Is December a good time to visit Nampa?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

0.1
Sightseeing
11th-best month of the year
0.0
Beach & pool
10th-best month of the year

December is a weaker month for outdoor sightseeing in Nampa.

What to pack for Nampa in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, Nampa sees daytime highs around 40°F and nights near 28°F. Pack a warm layer. Worth having: a heavy coat and rain gear. About 9 days see rain.

a warm layera heavy coatrain gear

UV index in Nampa in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 1. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Nampa peaks around July 13 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 14 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 13UV 9Dec 14UV 1
UV index (midday)Level
Jan2Low
Feb2Moderate
Mar4Moderate
Apr5High
May8Very high
Jun9Very high
Jul9Very high
Aug7Very high
Sep6High
Oct4Moderate
Nov2Low
Dec1Low

Air quality in Nampa in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.

Air quality in Nampa is worst in August — around 45 µg/m³ PM2.5 (poor), about 6.0× the cleanest month (December, 7 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0204060JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateModerateGoodAug 1742 µg/m³Dec 208 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb9Good
Mar10Good
Apr10Good
May10Good
Jun8Good
Jul20Moderate
Aug45Poor
Sep21Moderate
Oct15Moderate
Nov9Good
Dec7Good
Location & terrain

Where is Nampa?

Nampa sits at 43.5°N, 116.6°W, 2,516 ft above sea level, in United States. The nearest listed city is Kuna, 8.1 mi away.

Topography around Nampa

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Nampa.

Within 2 miles, the terrain around Nampa has only modest variations in elevation — a maximum elevation change of 144 ft around an average of 2,533 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 935 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 6,247 ft.

The land around Nampa is covered by artificial surfaces (35%) and trees (24%) within 2 miles, cropland (48%) and grassland (21%) within 10 miles, and grassland (68%) within 50 miles.

2 miles
144 ft
10 miles
935 ft
50 miles
6,247 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Kuna 8.1 mi · Meridian 9.9 mi · Caldwell 11 mi · Eagle 15 mi · Boise 19 mi · Twin Falls 126 mi · Pendleton 183 mi · Elko 191 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Nampa (43.5407°, -116.5635°, elevation 2,516 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).